Expression of HER2 and estrogen receptor alpha depends upon nuclear localization of Y-box binding protein-1 in human breast cancers

In our present study, we examined whether nuclear localization of Y-box binding protein-1 (YB-1) is associated with the expression of epidermal growth factor receptors (EGFR), hormone receptors, and other molecules affecting breast cancer prognosis. The expression of nuclear YB-1, clinicopathologic findings, and molecular markers [EGFR, HER2, estrogen receptor (ER)alpha, ER beta, progesterone receptor, chemokine (C-X-C motif) receptor 4 (CXCR4), phosphorylated Akt, and major vault protein/lung resistance protein] were immunohistochemically analyzed. The association of the expression of nuclear YB-1 and the molecular markers was examined in breast cancer cell lines using microarrays, quantitative real-time PCR, and Western blot analyses. Knockdown of YB-1 with siRNA significantly reduced EGFR, HER2, and ER alpha expression in ER alpha-positive, but not ER alpha-negative, breast cancer cell lines. Nuclear YB-1 expression was positively correlated with HER2 (P = 0.0153) and negatively correlated with ER alpha (P = 0.0122) and CXCR4 (P = 0.0166) in human breast cancer clinical specimens but was not correlated with EGFR expression. Nuclear YB-1 expression was an independent prognostic factor for overall (P = 0.0139) and progression-free (P = 0.0280) survival. In conclusion, nuclear YB-1 expression might be essential for the acquisition of malignant characteristics via HER2-Akt-dependent pathways in breast cancer patients. The nuclear localization of YB-1 could be an important therapeutic target against not only multidrug resistance but also tumor growth dependent on HER2 and ER alpha.     

YB-1在青年型乳腺癌组织中的表达及意义

目的:探讨YB-1(Y-box binding protein 1)在青年型乳腺癌组织中的表达及意义。方法:应用免疫组织化学方法研究YB-1蛋白在青年型乳腺癌组织中的表达,并结合病理组织学类型、病理分级等临床特征分析YB-1在青年型乳腺癌组织中的表达意义;依据ER、PR、HER-2、CK5/6表达对青年型乳腺癌进行分子分型(Luminal-A、Luminal-B、HER2+和Basal-like 4个分子亚型),并分析其与YB-1表达的关系。结果:HE结果显示64例青年型乳腺癌病理组织学分类主要为浸润性导管癌,占59.4%。免疫组化结果显示64例青年型乳腺癌组织中YB-1阳性率为92.2%,其中细胞核阳性表达率53.1%,细胞浆阳性表达率39.1%。肿瘤>2cm的患者占59.4%,YB-1主要表达在细胞核(40.6%),患者肿瘤?2cm占37.5%,YB-1则主要在细胞浆表达(20.3%),YB-1表达类型与肿瘤大小有显著统计学意义(P=0.036)。组织学3级所占比例最高,占48.4%,且多为YB-1细胞核表达(37.5%),乳腺癌不同的组织学分级间YB-1的表达率不同(P=0.000);青年型乳腺癌患者发生淋巴结转移的比例高(84.4%),其中N3期所占比例最高,占40.6%,YB-1主要在细胞核表达,占31.3%,胞浆表达占7.8%。青年型乳腺癌分子分型中主最多见的是Luminal-B型,占46.9%,YB-1主要表达在细胞核(32.8%),浆表达仅占9.4%,统计分析显示YB-1表达的核浆分布特点与青年型乳腺癌分子分型有关(P=0.04)。结论:YB-1在青年型乳腺癌组织中的表达特点与肿瘤大小、病理组织分级及淋巴结状态有一定关系,细胞核阳性主要见于肿瘤>2cm的患者,而细胞浆阳性主要见于肿瘤?2cm的患者,且YB-1细胞核表达主要为组织学3级,且青年型乳腺癌淋巴结转移率高,YB-1主要在细胞核表达;青年型乳腺癌不同分子分型中YB-1蛋白表达存在差异,YB-1可能成为青年型乳腺癌防治的新的分子靶点。     

Decreased levels of hypoxic cells in gefitinib treated ER<Superscript>+</Superscript> HER-2 overexpressing MCF-7 breast cancer tumors are associated with hyperactivation of the mTOR pathway: therapeutic implications for combination therapy with rapamycin

Developing novel synergistic and more effective combination treatments is necessary for better management of breast cancer in the clinic. It is established that HER-2 overexpressing breast cancers are sensitive to the HER-1 (epidermal growth factor receptor (EGFR)) inhibitor gefitinib, but that this targeted agent produces only moderate therapeutic effects in vivo. Here, we use a model of ER(+) HER-2 overexpressing MCF-7 breast cancer (MCF-7(HER-2)) to identify, as broadly as possible, the in vivo microenvironmental and molecular therapeutic responses to gefitinib to predict a therapeutically viable target for gefitinib-based combination treatment. Our data show a link between in vivo reductions in tumor hypoxia (3-fold decrease, P = 0.002) and elevated activity of the mTOR pathway (3.8-fold increase in phospho-p70-S6K protein, P = 0.006) in gefitinib treated MCF-7(HER-2) tumors. Despite decreased levels of phosphorylated EGFR, HER-2 and Erk1/2 (P = 0.081, 0.005 and 0.034, respectively) the expression of phospho-AKT was not reduced in MCF-7(HER-2) tumors after gefitinib treatment. Levels of ERalpha receptor were, however, 1.8-fold higher in gefitinib treated compared to control tumors (P = 0.008). Based on these results we predict that gefitinib activity against ER(+) HER-2 overexpressing EGFR co-expressing breast cancers should be enhanced if used with agents that target the mTOR pathway. In vitro studies using MCF-7(HER-2) and BT474 breast cancer cells exposed to gefitinib and rapamycin in combination show that this combination produced significantly greater growth inhibitory effects than either of the drugs alone. Chou and Talalay analysis of the data suggested that combination of gefitinib and rapamycin was synergistic (CI < 1) at a number of selected drug ratios and over a broad range of effective doses.     

Expression of erbB/HER receptors, heregulin and p38 in primary breast cancer using quantitative immunohistochemistry

The purpose of this study was to investigate the frequency of expression of the erbB/HER family of growth factor receptors, their ligand heregulin, and the two different signaling pathways p38 and mitogen-activated protein kinase (MAPK), as well as the status of HER-2 phosphorylation in tumor specimens from patients with primary breast cancer. The level of expression of these proteins was measured by quantitative immunohistochemistry combined with microscope-based image analysis in paraffin-embedded breast cancer tissue from 35 patients. The frequency of expression was: EGFR (51%), HER-2 (54%), P-HER-2 (48%), HER-3 (48%), HER-4 (57%), heregulin (48%), p38 (17%), MAPK (48%). There was evidence of associations among the coexpression of heregulin, EGFR, HER-2, and HER-3. Also, there was evidence of a positive association between P-MAPK and HER-4. HER-3 was expressed at high levels in patients younger than 50 years of age. There was a trend for expression of higher levels of HER-4 in tumors larger than 2 cm. The expression of EGFR, HER-2, heregulin, p38 and MAPK was independent of age, tumor size, number of lymph nodes involved or hormone receptor status. The HER family of growth factor receptors appear to be regulated independently in invasive breast cancer. Assessing the expression of multiple tumor markers by quantitative immuno-histochemistry is feasible. Further research is needed to determine the prognostic and predictive roles of the various associations between HER receptors, their ligands and signal transduction molecules in patients with early-stage breast cancer.     

Expression of the HER family mRNA in breast cancer tissue and association with cell cycle inhibitors p21(waf1) and p27(kip1)

BACKGROUND: The HER family of the receptor tyrosine kinases epidermal growth factor receptor (EGFR), HER2, HER3 and HER4 are involved in the pathogenesis of many human malignancies. Although there is extensive literature on the expression of single HER-2 and EGFR receptors in breast cancer, little is known concerning the simultaneous expression at the mRNA level of these four receptors in human breast tissue and their influence in downstream signaling pathways that control cell cycle and proliferation. MATERIALS AND METHODS: The mRNA expression pattern of the four HER-receptors has been investigated and correlated with the expression of the cyclin-dependent kinase (CDK) inhibitors p21(Waf1) and p27(Kip1) in 67 breast cancer specimens. RESULTS: A positive correlation between HER-3 and HER-4 mRNA levels and a negative correlation between HER-2 and HER-3 was found. Compared to normal breast tissue, all four receptors were overexpressed in breast tumors and the strongest overexpression was found for HER-3 (p = 0.001). HER-4 expression was inversely related to histopathological grading (HPG), suggesting that elevated HER-4 mRNA expressions could be a biological marker of a more differentiated phenotype. The expression of p21(Waf1) protein was higher in HER-2-negative tumors, compared to HER-2-positive breast carcinomas. Compared to normal breast tissue, p21delta, the 19 kDa degraded form of p21 protein, was markedly expressed in breast cancer (p < 0.001). Conversely, p27(Kip1) was positively associated with HER-2 receptor and inversely associated with HER-3. CONCLUSION: The HER family members are overexpressed in breast cancer. Complex patterns of HER family expression were observed and the effect on cell cycle regulation was dependent on that pattern.     

Tissue microarray-based studies of patients with lymph node negative breast carcinoma show that met expression is associated with worse outcome but is not correlated with epidermal growth factor family receptors

BACKGROUND: It has been shown that receptor tyrosine kinases (RTKs) predict outcome in patients with breast carcinoma. Although RTKs are a large family, HER-2, epidermal growth factor receptor (EGFR), Met (hepatocyte growth factor receptor), and others all have shown the ability to predict outcome. However, it remains unclear whether these markers are defining the same subpopulation of patients with breast carcinoma. In this study, the authors attempted to determine the correlation between RTKs on the basis of their ability to stratify a population according to outcome. METHODS: The authors used tissue microarray technology to study 324 patients with lymph node negative breast carcinoma who had 20-40 years of follow-up. Expression was assessed using immunohistochemical stains for Met, EFGR, fibroblast growth factor receptor (FGFR), and HER-2. Expression levels were assessed by two observers, and correlations were analyzed. Standard pathology information, including tumor size, nuclear grade, Ki-67 receptor status, and estrogen and progesterone receptor expression levels, also was collected. RESULTS: RTK expression in the study cohort revealed two strong correlations. Specifically, HER-2 and EGFR showed similar expression patterns (P < 0.0001), and Met cytoplasmic domain and FGFR cytoplasmic staining showed similar expression patterns (P < 0.0001), but no correlation was found between the two groups. Of these RTKs, only high levels of Met cytoplasmic domain showed significance as a prognostic marker defining a shortened survival compared with the rest of the population (P = 0.0035; relative risk, 2.04). In the same group of patients, HER-2, hormone receptor status, and other RTK family receptors were not correlated with outcome. In multivariate analysis, only Met cytoplasmic domain and tumor size showed independent predictive value. CONCLUSIONS: The current results indicate that the cytoplasmic domain of Met shows a unique staining pattern and defines a set of patients unique from the set of patients defined by overexpression of HER-2, EGFR, or hormone receptors. Furthermore, this group of patients is associated tightly and independently with worse outcome.     

Immunofluorometric analysis of p53 protein and prostate-specific antigen in breast tumours and their association with other prognostic indicators.

Mutation and overexpression of p53 occurs in 20-40% of breast cancers and has been shown to be an independent prognostic indicator. Recently we have demonstrated prostate-specific antigen (PSA) expression in breast tumours to be suggestive of favourable prognosis, but quantitative relationships between PSA and p53, and between these and other prognostic factors in breast cancer, have not been investigated. Time-resolved immunofluorometric procedures were used to quantify both p53 protein and PSA in 200 breast tumour extracts, which were also assayed for oestrogen (ER) and progesterone receptors (PGR), epidermal growth factor receptors (EGFR), cathepsin D and HER-2/neu, and characterised for S-phase fraction and DNA ploidy. Weak Spearman correlations were found between p53 and ER (r = - 0.18, P = 0.010), PGR (r = - 0.15, P = 0.0385) and S-phase fraction (r = 0.17, P = 0.016), while PSA was correlated only with PGR (r = 0.16, P = 0.025). Wilcoxon rank sum analysis revealed that levels of ER (P = 0.0001), PGR (P = 0.0001), S-phase fraction (P = 0.0001) and EGFR (P = 0.0014) differed significantly between the two groups categorised as p53 negative or p53 positive. Tumours classified as PSA negative or PSA positive were found to differ with respect to PGR (P = 0.0091) and S-phase fraction (P = 0.011) in a similar analysis. Contingency tables indicated significant negative associations between the status of p53 and that of ER (P = 0.003) and PGR (P = 0.001) and between PSA and S-phase fraction (P = 0.012), and positive associations between p53 and EGFR (P = 0.017), HER-2/neu (P = 0.008), S-phase fraction (P = 0.001) and aneuploidy (P = 0.007), and between PSA and both ER (P = 0.061) and PGR (P = 0.010). No significant associations were found between p53 and PSA. Our results demonstrate that the presence of p53 in breast tumours relates to several other variables which are suspected to predict aggressive tumour phenotypes and that the presence of PSA relates to variables associated with good prognosis.     

Combination of EGFR, HER-2/neu, and HER-3 is a stronger predictor for the outcome of oral squamous cell carcinoma than any individual family members.

In a series of 111 patients with squamous cell carcinoma (SCC), we used immunohistochemistry to examine the expression levels of four epidermal growth factor receptor (EGFR) family members (EGFR, HER-2/neu, HER-3, and HER-4). Expression of the EGFR members was not significantly associated with tumor size. However, their expressions (except for HER-4) were significantly associated with the presence of lymph node metastasis, and all of them were significantly associated with distant metastasis. We further examined the association between the expression levels of the EGFR members and the survival rates in 47 oral SCC patients whose detailed clinical follow-ups were available. The expression of all EGFR members was significantly associated with shortened patient survival, and the association was strongest for HER-2/neu. Furthermore, the combination of HER-2, HER-3, and EGFR but not HER-4 significantly improved the predicting power. The expression level of HER-2/neu was significantly correlated with that of EGFR or HER-3. Similar coexpression patterns were also observed in three oral SCC cell lines studied, but not in four other head and neck SCC cell lines. Taken together, these results indicated that expression levels of EGFR, HER-2/ neu, and HER-3 may help predict the outcome of patients with oral SCC.     

PGE2通过EP1受体促进肝癌细胞生长和侵袭的研究进展

前列腺素E2（PGE2）是一种参与肝癌细胞生长与侵袭的重要细胞因子。PGE2通过与细胞膜表面的EP受体结合来发挥其调控肿瘤发生、发展的作用。在肝癌中,PGE2通过前列腺素E受体1（EP1）受体调节EGFR／PI3K／Akt、Src／EGFR／p44／42 MAPK／mTOR等信号通路影响Survivin、YB-1等关键物质,促进肝癌细胞生长和侵袭。现就近年来PGE2通过EP1受体促进肝癌细胞生长和侵袭作用机制的研究进行综述。     

乳腺浸润性导管癌组织Ki-67表达及其分子分型的意义

目的:探讨Ki-67增殖抗原在乳腺浸润性导管癌组织中的表达及与临床病理特征、雌激素受体(ER)、孕激素受体(PR)、人表皮生长因子受体-2(C-erbB-2)和抑癌基因p53的关系.方法:采用Elivison二步法进行免疫组化染色,检测102例单侧乳腺浸润性导管癌组织中Ki-67、ER、PR、C-erbB-2和p53的表达水平,并结合患者相关临床资料进行分析.结果:Ki-67高表达(≥14％)比例占82.4％ (84/102).不同分子亚型中,luminalA型Ki-67表达率最低,三阴性(导管)最高.Ki-67表达水平与单侧浸润性导管癌患者的淋巴结转移(x2=5.007,P=0.025)、TNM分期(u=705.000,P=0.032)和组织分级(单侧Fisher:P=0.042)有明显的相关性,与患者的年龄(t=1.996,P=0.052)、肿块大小(u=859.000,P=0.502)和侵犯脉管情况(xc2=0.762,P=0.383)无明显的相关性.Ki-67表达水平与ER(r=-0.273,P=0.005)、PR(r=-0.332,P=0.001)表达程度呈负相关;与C-erbB-2(r=0.327,P=0.001)、p53(r=0.343,P=0.000)表达程度呈正相关.结论:Ki-67表达与目前乳腺癌分子分型相关,其高表达是预后不良因素.     

Her-2/neu and urokinase-type plasminogen activator and its inhibitor in breast cancer.

PURPOSE: Recent studies suggest that HER-2/neu specifically promotes the invasive capacity of tumor cells by up-regulating secretion of the proteolytic enzyme, urokinase-type plasminogen activator (uPA), or its inhibitor, plasminogen activator inhibitor-1 (PAI-1), in colon and gastric cancer. It was the purpose of this study to: (a) evaluate the association between HER-2/neu and uPA and PAI-1 expression in a large primary breast cancer cohort; (b) perform the first multivariate analysis, including HER-2/neu, uPA, and PAI-1 in breast cancer; and (c) define the effect of HER-2/neu overexpression on uPA and PAI-1 expression in breast cancer cells. EXPERIMENTAL DESIGN: HER-2/neu, uPA, and PAI-1 were measured as continuous variables by ELISA in primary breast cancer tissue extracts from 587 patients with clinical follow-up and analyzed for correlations with clinical outcome. Furthermore, a full-length human HER-2/neu cDNA was introduced into five human breast cancer cell lines to define the effects of HER-2/neu overexpression on uPA and PAI-1 expression. In addition, we tested whether HER-2/neu antibodies could reverse any given alteration of uPA and PAI-1 levels. RESULTS: Our findings indicate a weak positive association between HER-2/neu and uPA (r = 0.147; P < 0.001) and no association between HER-2/neu and PAI-1 (r = 0.07; P = 0.085). HER-2/neu overexpression (> or =400 fmol/mg) and high levels of uPA/PAI-1 (> or =5.5 ng/mg and/or > or =14 ng/mg, respectively) were significantly associated with shorter disease-free survival (DFS; P < 0.001 and P = 0.003) and metastasis-free survival (MFS; P = 0.015 and P < 0.001). Multivariate analysis revealed prognostic independence between HER-2/neu and the uPA/PAI-1 axis for DFS and MFS. Both uPA and PAI-1 had no significant discriminatory effect among HER-2/neu-positive patients for DFS. The prognostic value of HER-2/neu overexpression for MFS, however, was significantly enhanced by elevated uPA expression (P = 0.053). Stable transfection of the HER-2/neu gene into multiple human breast cancer cell lines resulted in consistent down-regulation of uPA or PAI-1 expression. In addition, anti-HER-2/neu antibodies did not significantly affect uPA or PAI-1 expression in human cancer cell lines naturally overexpressing HER-2/neu. CONCLUSIONS: The present findings suggest that the invasive phenotype elicited by HER-2/neu overexpression in breast cancer is not a direct effect of uPA or PAI-1 expression. HER-2/neu and the uPA/PAI-1 axis have been shown to affect the invasive capacity of breast cancer independently. Determination of uPA can provide significant additional prognostic information for MFS in HER-2/neu-positive and -negative patients.     

乳腺癌组织HR与HER-2和SATB1表达相关性研究

目的：检测乳腺癌组织中激素受体（hormonereceptor,HR）、人表皮生长因子受体2（humanepidermalgrowthfactOrreceptor2,HER-2）和特异性核基质结合蛋白（specialATrichsequencebindingprotein1,SATB1）的表达,探讨HR与HER-2、SATB1及临床病理参数的关系。方法：应用免疫组织化学方法检测乳腺癌患者雌激素受体（estrogenre-ceptor,ER）、孕激素受体（progesteronereceptor,PR）、HER-2及SATB1蛋白的表达,荧光原位杂交方法检测HER-2基因扩增状态,统计学方法分析HR（包括ER及PR）的表达与HER-2、SATB1及临床病理参数之间的相关性。结果：乳腺癌组织ER及PR的表达均与患者年龄正相关（r=0．286,P=0．010;r=0．249,P=0．026）,ER的表达与肿瘤分级负相关（r=-0．306,P=0．006）;ER及PR的表达与肿瘤大小、组织学类型、淋巴转移情况及TNM分期均无明显相关性,P值均〉0．05。HR的表达与SATB1、HER-2及SATB1／HER2双阳性表达均呈负相关关系（r=-0．248,P=0．027;r=-0．392,P〈0．001;r=-0．150,P〈0．001）。结论：HR阳性患者治疗及预后相对较好;乳腺癌组织HR的表达与HER-2和SATB1呈负相关关系,三者之间可能存在相互联系的信号通路。     

The outcome of heregulin-induced activation of ovarian cancer cells depends on the relative levels of HER-2 and HER-3 expression.

Members of the epidermal growth factor receptor family of tyrosine kinases, including epidermal growth factor receptor, c-erbB-2 (HER-2), c-erbB-3 (HER-3), and c-erbB-4 (HER-4), can be coexpressed at different levels in nonhematopoietic tissues. Amplification and overexpression of HER-2 is found in approximately one-third of cancers that arise in the breast and ovary. In our previous studies, heregulin (HRG) and anti-HER-2 antibodies inhibited proliferation, increased invasiveness, and enhanced tyrosine autophosphorylation of SKBr3 breast cancer cells that overexpressed HER-2. In the present report, the effects of HRG and anti-HER-2 antibody have been compared in six ovarian cancer cell lines. HRG inhibited anchorage-independent growth of SKOv3 cells that overexpressed HER-2 (10(5) receptors/cell) but stimulated the growth of OVCA420, OVCA429, OVCA432, OVCA433, and OVCAR-3 cells that expressed lower levels of the receptor (10(4) receptors/cell). Thus, cell lines with a high level of HER-2 relative to HER-3 or HER-4 were growth inhibited, whereas cell lines with lower levels of HER-2 were growth stimulated by HRG. Stimulation or inhibition of clonogenic growth did not correlate with endogenous expression of HRG or with the impact of exogenous HRG on phosphorylation of HER-2, HER-3, or HER-4. Anti-HER-2 antibodies inhibited the growth of SKOv3 cells but failed to affect the growth of the other cell lines. In OVCAR-3 cells that had been transfected with HER-2 cDNA to increase expression to 10(5) receptors/cell, HRG inhibited rather than stimulated growth. Conversely, when HER-2 expression by SKOv3 cells was downregulated by transfection of the viral E1A gene, HRG stimulated rather than inhibited growth. To evaluate the relative importance of HER-3 and HER-4, NIH 3T3 cells were cotransfected with HER-2 and HER-3 or with HER-2 and HER-4. HRG inhibited the growth of cells with a high ratio of HER-2:HER-3, whereas HRG stimulated the growth of cells with low levels of the two receptors. In cells that express only HER-2 and HER-4, HRG stimulated the growth of cells that expressed HER-4 independent of HER-2 levels. Anti-HER-2 antibodies inhibited the growth of transfectants with high levels of HER-2 expression independent of HER-3 or HER-4 expression. In ovarian cancer cells that express all three receptors, the relative levels of HER-2 and HER-3 appear to determine the response to HRG. Taken together, these studies support the concept that the level of HER-2 expression can modulate response to HRG, determining whether the response is stimulatory or inhibitory. In contrast, agonistic antibodies that bind to HER-2 alone inhibit anchorage-independent growth but fail to mimic HRG's ability to stimulate growth of cells with low HER-2: HER-3 ratios.     

Lack of prognostic significance of epidermal growth factor receptor and the oncoprotein p185HER-2 in patients with systemically untreated non-small-cell lung cancer: an immunohistochemical study on cryosections.

The prognostic role of the epidermal growth factor receptor (EGFR) and the related receptor p185HER-2 in lung cancer is as yet undefined. We investigated the immunohistochemical expression of EGFR (monoclonal antibody R1; Amersham) and p185HER-2 (polyclonal antibody A485; Dako) in cryosections. A total of 186 unselected and systemically untreated patients with non-small-cell lung cancer (NSCLC) diagnosed and treated at Odense University Hospital, Denmark, were included. Median follow-up period was 66 months. EGFR and p185HER-2 was highly expressed in 55% and 26% of cases respectively. Expression of EGFR was independent of p185HER-2 expression. The expression of EGFR was higher in squamous cell carcinomas whereas the level of p185HER-2 staining was higher in adenocarcinomas. Expression of either or both receptors was not correlated with age, histological grading, stage and prognosis. We conclude that immunohistochemical detection of these growth factor receptors failed to demonstrate a prognostic significance in patients operated on for NSCLC.     

HER-2 amplification, HER-1 expression, and tamoxifen response in estrogen receptor-positive metastatic breast cancer: a southwest oncology group study.

PURPOSE: Preclinical data indicate that expression of the ErbB family of receptors, such as HER-2 and HER-1 (EGFR) may be involved in endocrine resistance. Evidence of resistance from clinical studies has been inconsistent. The present study examined whether HER-2 gene amplification or HER-1 expression predicted response to tamoxifen. PATIENTS AND METHODS: Three hundred and forty nine patients had estrogen receptor (ER)-positive breast cancer and received daily tamoxifen as initial therapy for advanced disease. HER-2 gene amplification, detected by fluorescence in situ hybridization, and HER-1 expression, evaluated by immunohistochemistry, was determined on 136 and 204 patients, respectively. RESULTS: HER-2 amplification was correlated with lower ER (P = 0.02), HER-1 positivity (P = 0.004), and HER-2 protein overexpression (P < 0.00001). The response rate was 56% for HER-2 non-amplified versus 47% for HER-2 amplified tumors (P = 0.38), and 58% for HER-1-negative versus 36% for HER-1-positive (P = 0.05). Time to treatment failure (TTF) was 7 months for non-amplified HER-2 tumors and 5 months (P = 0.007) for amplified HER-2 tumors, and there was a trend toward a better overall survival (OS) in patients with non-amplified HER-2 tumors (median 31 versus 25 months, respectively, P = 0.07). For positive versus negative HER-1 tumors, TTF was 4 versus 8 months (P = 0.08) and median survival was 24 versus 31 months (P = 0.41). Combining HER-1 expression and HER-2 gene status, patients with both negative HER-1 expression and non-amplified HER-2 had longer TTF (P = 0.001) and OS (P = 0.03) than if either were positive. In multivariate analysis, HER-2 was not an independent factor for TTF and OS, although HER-1 was significant for TTF only (P 相似文献